You can check whether any prog has been installed (even if you
can´t find the relevant icons in the menu) by typing in cmd line : sudo
apt-get install <prog>
If already installed this will be reported accordingly . If not ,it will be
installed.

Alternatively you can goto or install synaptic where you can see all the
progs/apps installed on your machine ,by scrolling all the apps or apps in
a specific category.

Personally I prefer the command line method.